Keyboard



FIG. 1 is a top plan view of a keyboard, showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a front elevation thereof;

FIG. 4 is a rear elevation thereof;

FIG. 5 is a left side view; and

FIG. 6 is a right side view thereof; and,

FIG. 7 is a top front perspective view thereof. 

The ornamental design for a keyboard, as shown and described. 